Hi, Is it possible to compute the elastic energy for a simple 2D cube before we solve the system? Because I checked the displacement gradients and they are 0 due to having no solution probably.
Hence, I wonder how would someone be able to compute the elastic energy with the following formula: psi = 0.5 * lambda * tr_eps * tr_eps + mu * tr_eps_2; with tr_eps = trace(eps); tr_eps_2 = trace(eps * eps); Here eps is the strain tensor and lambda as well as mu are the lamé parameters, respectively. In order to compute the strain tensor eps I need the displacement gradients: eps = 0.5 * (grad_u + transpose(grad_u)); And from what I checked, the get_strain() function from step-18 doesn't give me the same strain tensor. It seems more like a B-operator to me. If I compute the elastic energy after I solved the system, how am I able to store the energy values for each cell, so I can have access to it all the time. >From Timo Heister and Thomas Wick's phase-field crack examples I learned that they compute energy by means of the compute_energy() function, but it seems to me like they just output the value and it is not further used during computation. Kind regards, S. A. Mohseni -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
